The opium war was a battle between China and Britain that occurred from 1839 to 1842. The British opium trade in China started the world’s first drug war, in the 19th century. In the 15th century when opium was first introduced to China, it was used as medicine to treat diseases. It wasn't until the 16th century, when the British started mixing the opium with tobacco allowing the Chinese to smoke it and become addicted.
China was trading tea to Britain, however China was a self sufficient country and didn't want anything from Britain. Britain didn't want it to become a one sided trade so they decided to import opium drugs to China. As a result a large amount of China's population weakened. When the Chinese government found out that opium was still being brought to China even after the restrictions were set, a letter was written to Queen Victoria. The letter stated that if the opium was so harmful in its effects that Britain had made opium trading and consumption illegal in England, then why was England exporting such harmful products to other countries. Queen Victoria never had the letter delivered to her.
Soon after Britain demanded that China put an end to the anti-opium campaign. But Lin refused to end it. In 1840, British gunboats arrived and attacked China, destroying many coastal cities. China was not prepared for this war because Britain had a technological advantage over them, such as weapons. China was eventually defeated by Great Britain, and was forced to sign the Treaty of Nanjing in 1842.